If you want to complete your collection of C.S. Lewis fiction, this volume will do that. (Note that about 1/3 of it overlaps with the stories included in Of Other Worlds by the same publisher and editor). “The Dark Tower” is a partial story (about 70 pages) about a parallel universe; the characters overlap a little with the “Space Trilogy.”
“The Man Born Blind” is a story of a man who is given sight and wants to understand light. “The Shoddy Lands” is a short study in perspective. “Ministering Angels” is about a trip to Mars (and reminds me of some of Isaac Asimov’s humor pieces). “Forms of Things Unknown” is about a dangerous trip to the moon. “After 10 Years” is a partial story (about 20 pages), a followup to a Greek myth.
In general, the science fiction is “just” a carrier to get us to places unknown rather than being integral to the story. The stories themselves are good (though sometimes rough), laced with myth in his trademark way.